Answer by xmoex for Installing glfw3 on ubuntu 13.04 - make error

For proprietary drivers see update & warning below

Try reinstalling libgl1-mesa-dev and libgl1-mesa-glx wich renews the libGL.so symlink without manual interference.

sudo apt-get install --reinstall libgl1-mesa-dev libgl1-mesa-glx

This worked for: Debian Wheezy

Update & Warning:

Turn's out the reinstallation of libgl1-mesa-dev and libgl1-mesa-glx renewed - as expected - the libGL.so symlink, but also broke my proprietary nvidia driver installation. After reinstalling the driver everything's fine. So in that case, it might be a good idea to just reinstall your proprietary driver.